Forming a pattern on a substrate

Abstract

A pattern is formed on a substrate by providing on the substrate a dielectric composition; defining a pattern in said dielectric; depositing metal and then micromachining the metal to provide the desired pattern on the substrate.

What is claimed is: 
     
       1. A process for forming a metallic pattern on a substrate for the fabrication of thin film structure for multichip packaging which comprises: a. providing a metal onto a substrate;   b. micromachining the metal down to a desired thickness;   c. depositing a photoresist layer on said metal;   d. defining desired pattern of circuit channels in said photoresist;   e. etching the desired metal pattern in the metal layer using the photoresist as the mask;   f. removing the remaining photoresist layer;   g. depositing a dielectric layer onto the metal and over the substrate;   h. micromachining the dielectric layer to the level of the metal to provide the desired pattern of dielectric material between the metal of the metallic pattern; wherein said micromachining is single crystal diamond to provide planar metallic pattern in which the flatness is within 1 micron over 1 metal length and the average roughness of the metallic pattern is 0.02 to 0.005 micron.   
     
     
       2. The process of claim 1 wherein said dielectric layer is a polyimide precursor layer. 
     
     
       3. The process of claim 1 wherein the metal includes copper. 
     
     
       4. The process of claim 1 wherein said desired thickness of said metal is about 2 microns to about 40 microns. 
     
     
       5. The process of claim 1 wherein said desired thickness of said metal is about 5 microns.